<template>
   <!-- 输入框 -->
   <header class="header">
      <h1>小黑记事本</h1>
      <input
      @keyup.enter="handleAdd"
      v-model="todoName" placeholder="请输入任务" class="new-todo" />
      <button @click="handleAdd" class="add">添加任务</button>
    </header>

</template>

<script>
export default {
    data () {
        return {
            todoName: '',
        }
    },
    methods: {
       
        handleAdd() {
            if(this.todoName.trim() === '') {
            alert('任务不能为空！')
            return 
        }
            this.$emit('add',this.todoName)
            this.todoName = ''
        }
    }
}
</script>

<style>

</style>